Pump or compressor.



E. W. H. McM| CHAEL.

PUMP 0R COMPRESSOR.

APPLICATION FILED SEPT. 4. 1914.

Patented July 27, 1915.

L E M m c HM V NH IIB R H M m L l W. T N R E M ATTORNEY.

ERNEST VIILLIAM HERBERT McMICI-IAEL, OF- WALTHAM CROSS, ENG-LAND.

PUMP 0R, COMPRESSOR.

Specification of Letters Patent.

PatentedJuly-27, 1915.

Application filed September 4, 1914. Serial No. 860,210.

To all whom it may concern:

Be it known that I, ERNEST WILLIAM 9f Great Britain, residing at The Lea Valley Engineering Company, Limited, of Riverside lVorks, vValtham Cross, in the county of Essex, England, have invented new and useful Improvements in or Connected'with Pumps or Compressors, of which the following is a specification.

The invention relates to improvements in or connected with pumps or compressors for various purposes and more especially intended for use in connection with refrigerating machines.

Heretofore, it has sometimes been the practice to provide the pumps or compressors of refrigerating machines with a thin disk of metal constituting a safety valve, which bursts when the pressure in the pump or compressor exceeds a predetermined limit.

The bursting of this disk has heretofore involved the loss of the whole or a large portion of the working medium and in the case of pumps or compressors using such working mediums as ammonia (NI-I or sulfur dioXid (SO it has not been the usual practice to use a safety disk owing to the fact that obnoxious fumes would be liberated on the bursting of such disk.

Now the object of the present invention is to provide a simple and efficient means whereby a safety disk may be employed without the loss above indicated.

The above object and other advantageous ends I secure as hereinafter set forth, reference being had to the accompanyingdrawing which is a transverse section through a portion of a pump or compressorconstructed according to the present invention.

In the drawing, 1 represents the cylinder of the pump or compressor, 2 the discharge outlet of the pump, 3 the delivery valve, & the delivery valve guide, 5 the usual safety disk and 6 the dischargeoutlet for normal working.

According to the present invention, the safety disk 5, which is formed of thin sheet metal, is placed at the outer end of the delivery valve guide 4 of the pump or compressor 1. The delivery valve 3 is on the inner face 7 formed preferably ofconical shape to co-act with a seat 8 in a plug 9 forming the cylinder head or end so as to close the discharge outlet 2 from the pump or compressor 1, while at the outer face 10 said valve 3 is shaped to co-act with a seat 11 at the inner end of the delivery valve HERBERT MoMIoI-IAnL, a subject of the King guide 4-. The valve 3 is normally kept on its main seat 7 by a spring 12 surrounding its rod 13 or by its own weight and said rod 13 is provided with longitudinal ways 11 so arranged that the working medium may have access to the safety disk 5.

When the pressure in the pump or compressor exceeds the predetermined limit (as in the event of the attendant starting up'the machine with the delivery stop valve (not shown) closed) the safety disk 5 will burst but immediately this happens the pressure in the pump or compressor 1 will force and retain the valve 3 with its outer face 10 against its seat 11 on the inner end of the valve guide st and thus prevent the working medium escaping past the burst disk into the atmosphere. The inner face 7 of the delivery valve 3 being now held off its seat 8, no further pressure can be generated by the compressor or pump 1. Upon the burst disk 5 being replaced by a new one the pressure in the space between the disk 5 and the valve seat 11 on the inner end of the valve guide 4 will gradually be filled with the working medium, due to slight leakage past the said valve seat 11. As soon as the pressure in this space equals the main internal pressure in the cylinder 1 the valve 3 will fall and rest upon its normal seat 8. The pump or compressor 1 will then resume its ordinary work, subject to the cause of the excessive pressure having been removed. The safety disk 5 is inclosed by a perforated cap 15 screwing on to the delivery valve guide 1 so that a burst disk can easily be replaced by a new one.

It will be understood that in a double-acting pump a safety device constructed as hereinbefore described would be fitted to the delivery valve at each end of the pump or compressor and'that the apparatus might be arranged horizontally.

What I claim is 1. The combination, in a pump or compressor, of a discharge from the pump cylinder, a double-acting valve controlling said outlet and having two faces, a guide for said valve, a safety disk, relief ways for permitting access of the working medium to said safety disk, a valve seat formed around the discharge outlet from the pump cylinder with which seat one face of the valve is adapted to co-act, a valve seat formed about the inner endof the valve guide With which the other face of the valve is adapted to 00- act, means for facilitating the replacing of a burst disk by a neW one and a discharge outlet for normal working above the valve.

2. The combination, in a pump or compressor, of a discharge outlet from the pump cylinder, a valve faced on both sides, a rod to said valve, a guidefor said valve rod, a safety disk placed at the outer end of said valve guide, grooves in the valve rod permitting access of the Working medium to the safety disk, a valve seat formed around the discharge outlet from the pump cylinder with which the inner face of the valve is adapted to co-act, a valve seat formed at the inner end of the valve guide With which the outer face of the valve is adapted to co-aot, a spring for returning the valve to its normal position to close the discharge outlet from the pump cylinder, a perforated removable cap screwing on to the outer end of the valve guide for inclosing the safety disk and a discharge outlet for normal Working above the valve.

ERNEST WILLIAM HERBERT MGMIOHAEL.

Witnesses:

BYFLEET Gr. HAVENOOROFT, James A HUDSON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, I). 0. 

